sfc: Use dev_kfree_skb() in efx_end_loopback()
sfc: Use dev_kfree_skb() in efx_end_loopback()

Fix CID 102619 in the Coverity report on Linux.

efx_end_loopback() iterates over an array of skb pointers of which
some may be null (if efx_begin_loopback() failed).  It should not use
dev_kfree_skb_irq(), which requires non-null pointers.  In practice
this is safe because it does not run in interrupt context and
therefore always ends up calling dev_kfree_skb(), which does allow
null pointers.  But we should make that explicit.

Signed-off-by: Ben Hutchings <0672176982fbc629cc374f31a7a45ae1671abf90@solarflare.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs