SFH: fix error return check for -ERESTARTSYS

Currently the check for the error return code -ERESTARTSYS is dead code
and never executed because a previous check for ret < 0 is catching this
and returning -ETIMEDOUT instead.  Fix this by checking for -ERESTARTSYS
before the more generic negative error code.

Addresses-Coverity: ("Logically dead code")
Fixes: 4b2c53d9

 ("SFH:Transport Driver to add support of AMD Sensor Fusion Hub (SFH)")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Sandeep Singh <sandeep.singh@amd.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>