Only update submodules if the source is in a git repo

This change just adds a check to verify that the build is happening
inside a git repo and that git is a valid command before trying
to update the submodules.

Use 'command -v' instead of 'which' to stay portable.

Change-Id: Idfa27645c3dbfd684f90002ecb01626d71eacc8f
Signed-off-by: Martin Roth <gaumless@gmail.com>
Reviewed-on: http://review.coreboot.org/8427
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

0 files changed, 0 insertions, 0 deletions