Use rm -f to avoid interactive prompts

This is required when not running as root to avoid prompts when
removing read-only files.

sysa/perl-5.003/perl-5.003.sh

@@ -12,14 +12,14 @@ src_prepare() {
     default
 
     # Regenerate bison files
-    rm perly.c perly.h
+    rm -f perly.c perly.h
     bison -d perly.y
     mv perly.tab.c perly.c
     mv perly.tab.h perly.h
 
     # Regenerate other prebuilt header files
     for file in embed keywords opcode; do
-        rm ${file}.h
+        rm -f ${file}.h
         perl ${file}.pl
     done
 }