util/genbuild_h: micro-adjust the regexp used to set COREBOOT_MAJOR_VERSION

On FreeBSD, every build target would show warnings from its
builtin printf().
Change the regexp to be compatible with BSD sed.
This will avoid noise like "printf: 4.14-1278-g5d74ccf1c3: not
completely converted".

Signed-off-by: Idwer Vollering <vidwer@gmail.com>
Signed-off-by: Jessica Clarke <jrtc27@jrtc27.com>
Change-Id: I1c0c260fd8d42e23a612a353a288e472cc068c8e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56803
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/util/genbuild_h/genbuild_h.sh b/util/genbuild_h/genbuild_h.sh
index c898fb6e..8c72ddf 100755
--- a/util/genbuild_h/genbuild_h.sh
+++ b/util/genbuild_h/genbuild_h.sh
@@ -70,7 +70,7 @@
 printf "#define COREBOOT_ORIGIN_GIT_REVISION \"$GITREV\"\n"
 
 printf "#define COREBOOT_EXTRA_VERSION \"%s\"\n" "$COREBOOT_EXTRA_VERSION"
-printf "#define COREBOOT_MAJOR_VERSION %d\n#define COREBOOT_MINOR_VERSION %d\n" `git describe --match [0-9].[0-9]* | sed 's/\([0-9]\)\.\([0-9]\+\).*/\1 \2/'`
+printf "#define COREBOOT_MAJOR_VERSION %d\n#define COREBOOT_MINOR_VERSION %d\n" `git describe --match [0-9].[0-9]* | sed 's/\([0-9]\)\.\([0-9][0-9]*\).*/\1 \2/'`
 printf "#define COREBOOT_BUILD \"$(our_date "$DATE")\"\n"
 printf "#define COREBOOT_BUILD_YEAR_BCD 0x$(our_date "$DATE" +%y)\n"
 printf "#define COREBOOT_BUILD_MONTH_BCD 0x$(our_date "$DATE" +%m)\n"