Inline ufshcd_outstanding_req_clear() since it only has one caller and
since its body is only one line long.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Stanley Chu <redacted>
Cc: Can Guo <redacted>
Cc: Asutosh Das <redacted>
Cc: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>

Reviewed-by: Avri Altman <avri.altman@wdc.com>