Use git log pretty printing arguments that are compatible with older versions of git

Author: brson

doc/Makefile

@@ -4,7 +4,7 @@ all: rust.pdf rust.html
 
 version.texi: Makefile rust.texi
 	git log -1 \
-      --format='@macro gitversion%n%h %ci%n@end macro%n' >$@
+      --pretty=format:'@macro gitversion%n%h %ci%n@end macro%n' >$@
 
 %.pdf: %.texi version.texi
 	texi2pdf $<

src/Makefile

@@ -297,7 +297,7 @@ all: $(CFG_RUSTC) $(MKFILES) $(GENERATED)
 
 boot/util/version.ml: Makefile
 	$(CFG_QUIET)git log -1 \
-      --format='let version = "prerelease (%h %ci)";;' >$@ || exit 1
+      --pretty=format:'let version = "prerelease (%h %ci)";;' >$@ || exit 1
 
 loc:
 	$(CFG_QUIET)wc -l $(BOOT_MLS) $(RUNTIME_CS) $(RUNTIME_HDR)