linux-perf: Fix build (unportable shell hack broke).

pkgs/os-specific/linux/kernel/perf.diff

@@ -0,0 +1,18 @@
+--- perf/config/utilities.mak.orig	2014-01-25 14:55:32.573320370 +0000
++++ perf/config/utilities.mak	2014-01-25 15:13:34.174337760 +0000
+@@ -186,9 +186,14 @@
+ endif
+ TRY_CC_MSG=echo "    CHK $(3)" 1>&2;
+ 
++define newline
++
++
++endef
++
+ try-cc = $(shell sh -c						  \
+ 	'TMP="$(OUTPUT)$(TMPOUT).$$$$";				  \
+ 	 $(TRY_CC_MSG)						  \
+-	 echo "$(1)" |						  \
++	 echo -e "$(subst $(newline),\\n,$(1))" | tee _test.c |   \
+ 	 $(CC) -x c - $(2) -o "$$TMP" $(TRY_CC_OUTPUT) && echo y; \
+ 	 rm -f "$$TMP"')

pkgs/os-specific/linux/kernel/perf.nix

@@ -12,6 +12,7 @@ stdenv.mkDerivation {
   preConfigure = ''
     cd tools/perf
     sed -i s,/usr/include/elfutils,$elfutils/include/elfutils, Makefile
+    patch -p1 < ${./perf.diff}
     [ -f bash_completion ] && sed -i 's,^have perf,_have perf,' bash_completion
     export makeFlags="DESTDIR=$out $makeFlags"
   '';