e2fsprogs: Add comment on why touch is needed

Commit b32f3b655189fd89dcfce084b6fda0d379300f75 added this code
but we could do with a commit so people realise why its there.

(From OE-Core rev: e4da78229f0bd67fd34928eafe48dbdc9e8da050)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/e2fsprogs/e2fsprogs_1.43.8.bb

@@ -25,6 +25,8 @@ EXTRA_OECONF_darwin = "--libdir=${base_libdir} --sbindir=${base_sbindir} --enabl
 PACKAGECONFIG ??= ""
 PACKAGECONFIG[fuse] = '--enable-fuse2fs,--disable-fuse2fs,fuse'
 
+# make locale rules sometimes fire, sometimes don't as git doesn't preserve
+# file mktime. Touch the files introducing non-determinism to the build
 do_compile_prepend (){
 	find ${S}/po -type f -name "*.po" -exec touch {} +
 }