common/rc: handle option with argument in _require_xfs_io_command()
Fix _require_xfs_io_command() to handle options that take arguments when
the argument is shown in the help text. E.g., it didn't work to run:
_require_xfs_io_command "add_enckey" "-k"
because the relevant line of the help text is:
-k KEY_ID -- ID of fscrypt-provisioning key containing the raw key
... but the grep command only matched "-k --", not "-k KEY_ID --".
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>