AOSP: mke2fs: print error and exit if MKE2FS_CONFIG is invalid

If the user specifies a configuration file by setting the environment
variable MKE2FS_CONFIG, make sure it's there and print an error message
and exit if it doesn't. Don't just ignore a nonexistent configuration
file.

Change-Id: Ief265b6e4fe149213b2a28d9eb90697e0fdbcb41
Signed-off-by: Daniel Mentz <danielmentz@google.com>
1 file changed