usb: gadget: composite: Show warning if function driver's descriptors are incomplete.

In the config_ep_by_speed_and_alt function, select the corresponding
descriptor through g->speed. But some legacy or not well designed
function drivers may not support the corresponding speed. So, we can
directly display warnings instead of causing kernel panic. At the
same time, it indicates the reasons in warning message.

Change-Id: Ib8c979663d9f04212bcc3ef4e1c0dc5be26c6958
Reviewed-by: Peter Chen <peter.chen@kernel.org>
Signed-off-by: Qihang Hu <huqihang@oppo.com>
Link: https://lore.kernel.org/r/20211110101129.462357-1-huqihang@oppo.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Mot-CRs-Fixed: (CR)
Reviewed-on: https://gerrit.mot.com/2264211


SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Igor Kovalenko <igork@motorola.com>
Submit-Approved: Jira Key