code cleanup

[winnie]

there are some compiler warnings which needs a fix:

setup.c: In function 'setup__move_panels_config_into_separate_file': 
setup.c:536: warning: assignment discards qualifiers from pointer target type 
cc -std=gnu99 -DHAVE_CONFIG_H -I. -I.. -DDATADIR=\""/usr/share/mc/"\" -DLOCALEDIR=\""/usr/share/locale"\" -DSAVERDIR=\""/usr/lib/mc/mc"\" -DSYSCONFDIR=\""/etc/mc/"\" -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I.. -g -O2 -g -Wall -O2 -c slint.c 
cc -std=gnu99 -DHAVE_CONFIG_H -I. -I.. -DDATADIR=\""/usr/share/mc/"\" -DLOCALEDIR=\""/usr/share/locale"\" -DSAVERDIR=\""/usr/lib/mc/mc"\" -DSYSCONFDIR=\""/etc/mc/"\" -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I.. -g -O2 -g -Wall -O2 -c subshell.c 
subshell.c: In function 'init_subshell': 
subshell.c:510: warning: too many arguments for format      
complete.c: In function 'try_complete': 
complete.c:767: warning: passing argument 2 of 'completion_matches' from incompatible pointer type 
complete.c:804: warning: passing argument 2 of 'completion_matches' from incompatible pointer type 
complete.c:811: warning: passing argument 2 of 'completion_matches' from incompatible pointer type 
complete.c:835: warning: passing argument 2 of 'completion_matches' from incompatible pointer type 
cc -std=gnu99 -DHAVE_CONFIG_H -I. -I.. -DDATADIR=\""/usr/share/mc/"\" -DLOCALEDIR=\""/usr/share/locale"\" -DSAVERDIR=\""/usr/lib/mc/mc"\" -DSYSCONFDIR=\""/etc/mc/"\" -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I.. -g -O2 -g -Wall -O2 -c cons.handler.c 
cc -std=gnu99 -DHAVE_CONFIG_H -I. -I.. -DDATADIR=\""/usr/share/mc/"\" -DLOCALEDIR=\""/usr/share/locale"\" -DSAVERDIR=\""/usr/lib/mc/mc"\" -DSYSCONFDIR=\""/etc/mc/"\" -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I.. -g -O2 -g -Wall -O2 -c dialog.c 
cc -std=gnu99 -DHAVE_CONFIG_H -I. -I.. -DDATADIR=\""/usr/share/mc/"\" -DLOCALEDIR=\""/usr/share/locale"\" -DSAVERDIR=\""/usr/lib/mc/mc"\" -DSYSCONFDIR=\""/etc/mc/"\" -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I.. -g -O2 -g -Wall -O2 -c dir.c 
cc -std=gnu99 -DHAVE_CONFIG_H -I. -I.. -DDATADIR=\""/usr/share/mc/"\" -DLOCALEDIR=\""/usr/share/locale"\" -DSAVERDIR=\""/usr/lib/mc/mc"\" -DSYSCONFDIR=\""/etc/mc/"\" -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I.. -g -O2 -g -Wall -O2 -c execute.c 
cc -std=gnu99 -DHAVE_CONFIG_H -I. -I.. -DDATADIR=\""/usr/share/mc/"\" -DLOCALEDIR=\""/usr/share/locale"\" -DSAVERDIR=\""/usr/lib/mc/mc"\" -DSYSCONFDIR=\""/etc/mc/"\" -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I.. -g -O2 -g -Wall -O2 -c ext.c 
cc -std=gnu99 -DHAVE_CONFIG_H -I. -I.. -DDATADIR=\""/usr/share/mc/"\" -DLOCALEDIR=\""/usr/share/locale"\" -DSAVERDIR=\""/usr/lib/mc/mc"\" -DSYSCONFDIR=\""/etc/mc/"\" -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I.. -g -O2 -g -Wall -O2 -c file.c 
file.c: In function 'transform_source': 
file.c:166: warning: passing argument 1 of 'str_fix_string' discards qualifiers from pointer target type