perf tools: Remove stale prototypes from builtin.h

Some, like prune_packed_objects() are clearly git specific, others
don't have implementations and some are used in just one place, make
them static.

Link: http://lkml.kernel.org/n/tip-faj3c5dnttf3hurv4pujut8n@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/perf.c

@@ -91,7 +91,7 @@ static int pager_command_config(const char *var, const char *value, void *data)
 }
 
 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
-int check_pager_config(const char *cmd)
+static int check_pager_config(const char *cmd)
 {
 	int err;
 	struct pager_config c;