usb: dwc3: remove a possible unnecessary 'out of memory' message

This patch removes a possible unnecessary out of memory message from
core.c as reported by checkpatch.pl:
   WARNING: Possible unnecessary 'out of memory' message

Signed-off-by: Kushagra Verma <kushagra765@outlook.com>
Link: https://lore.kernel.org/r/SI2PR01MB392926A7AFB821410770D7CFF8C19@SI2PR01MB3929.apcprd01.prod.exchangelabs.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>