fix MakeMaker issues with using wrong SHELL/GREP

A set of substitution is being processed to all target scripts with sed by
replacing some key words with the detected values at configure time, this
is exactly not compliant with cross compling, and will cause missing path
errors at run time like:
"/usr/bin/zgrep: line 230: /usr/bin/grep: No such file or directory"

Fixed by removing unneeded substitution and using real runtime paths
instead.

Signed-off-by: Ming Liu <ming.liu@windriver.com>

Upstream-Status: Pending

Index: gzip-1.3.12/Makefile.am
===================================================================
diff -urpN a/Makefile.am b/Makefile.am
--- a/Makefile.am	2013-11-30 10:06:09.402234871 +0800
+++ b/Makefile.am	2013-11-30 10:13:42.952236025 +0800
@@ -81,9 +81,8 @@ gzip.doc.gz: gzip.doc $(bin_PROGRAMS)
 SUFFIXES = .in
 .in:
 	$(AM_V_GEN)sed \
-		-e 's|/bin/sh|$(SHELL)|g' \
 		-e 's|[@]bindir@|'\''$(bindir)'\''|g' \
-		-e 's|[@]GREP@|$(GREP)|g' \
+		-e 's|[@]GREP@|$(base_bindir)/grep|g' \
 		-e 's|[@]VERSION@|$(VERSION)|g' \
 		$(srcdir)/$@.in >$@-t \
 	  && chmod a+x $@-t \