build: trivial simplification

SCRIPT_PYTHON_GEN is '$(patsubst %.py,%,$(SCRIPT_PYTHON))', so replace
'$(patsubst %.py,%,$(SCRIPT_PYTHON))' with it

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -1796,8 +1796,8 @@ $(patsubst %.perl,%,$(SCRIPT_PERL)) git-instaweb: % : unimplemented.sh
 endif # NO_PERL
 
 ifndef NO_PYTHON
-$(patsubst %.py,%,$(SCRIPT_PYTHON)): GIT-CFLAGS GIT-PREFIX GIT-PYTHON-VARS
-$(patsubst %.py,%,$(SCRIPT_PYTHON)): % : %.py
+$(SCRIPT_PYTHON_GEN): GIT-CFLAGS GIT-PREFIX GIT-PYTHON-VARS
+$(SCRIPT_PYTHON_GEN): % : %.py
 	$(QUIET_GEN)$(RM) $@ $@+ && \
 	INSTLIBDIR=`MAKEFLAGS= $(MAKE) -C git_remote_helpers -s \
 		--no-print-directory prefix='$(prefix_SQ)' DESTDIR='$(DESTDIR_SQ)' \
@@ -1809,7 +1809,7 @@ $(patsubst %.py,%,$(SCRIPT_PYTHON)): % : %.py
 	chmod +x $@+ && \
 	mv $@+ $@
 else # NO_PYTHON
-$(patsubst %.py,%,$(SCRIPT_PYTHON)): % : unimplemented.sh
+$(SCRIPT_PYTHON_GEN): % : unimplemented.sh
 	$(QUIET_GEN)$(RM) $@ $@+ && \
 	sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \
 	    -e 's|@@REASON@@|NO_PYTHON=$(NO_PYTHON)|g' \