staging: rtl8712: fix checkpatch long-line warning

This patch fixes these two long-line checkpatch warnings
in rtl871x_xmit.c:

WARNING: line over 80 characters
\#74: FILE: drivers/staging//rtl8712/rtl871x_xmit.c:74:
+       * Please allocate memory with the sz = (struct xmit_frame) * NR_XMITFRAME,

WARNING: line over 80 characters
\#79: FILE: drivers/staging//rtl8712/rtl871x_xmit.c:79:
+               kmalloc(NR_XMITFRAME * sizeof(struct xmit_frame) + 4, GFP_ATOMIC);

Signed-off-by: Aiman Najjar <aiman.najjar@hurranet.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/acd523d0d24cc81fae9eb933a066d87815587cee.1585508171.git.aiman.najjar@hurranet.com


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