Makefile: simplify by using SCRIPT_{PERL,SH}_GEN macros
Makefile: simplify by using SCRIPT_{PERL,SH}_GEN macros

SCRIPT_PERL_GEN is defined as $(patsubst %.perl,%,$(SCRIPT_PERL))
for use in targets like build-perl-script used by makefiles in
subdirectories that override SCRIPT_PERL (see v1.8.2-rc0~17^2,
"git-remote-mediawiki: use toplevel's Makefile", 2013-02-08).

The same expression is used in the rules that actually write the
generated perl scripts, and since these rules were introduced before
SCRIPT_PERL_GEN, they use the longhand instead of that macro.  Use the
macro to make reading easier.

Likewise for SCRIPT_SH_GEN.  The Python rules already got the same
simplification in v1.8.4-rc0~162^2~8 (2013-05-24).

Signed-off-by: Jonathan Nieder <b57189c5f2fd5b3daf3350a77fde90def1080fa5@gmail.com>
Reviewed-by: Jeff King <696e3fbcf235d40b6ea1ebd61c87cbea79d444e7@peff.net>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git