Fix objdir build bustage by not trying to install from the objdir a script that is in the srcdir. r=bryner

tools/jprof/Makefile.in

@@ -55,6 +55,7 @@ EXPORTS         := $(addprefix $(srcdir)/, $(EXPORTS))
 
 OTHER_LIBRARIES = $(LIBMALLOC)
 HELPER_SCRIPTS = jprofsig
+HELPER_SCRIPTS  := $(addprefix $(srcdir)/, $(HELPER_SCRIPTS))
 TARGETS := $(PROGRAM) $(OTHER_LIBRARIES) $(HELPER_SCRIPTS)
 
 include $(topsrcdir)/config/rules.mk