staging: rtl8188eu: remove unnecessary logging

staging: rtl8188eu: remove unnecessary logging

This commit fixes the following checkpatch.pl issues:

+               pr_debug("===> %s\n", __func__);

WARNING: Unnecessary ftrace-like logging - prefer using ftrace
158: FILE: drivers/staging/rtl8188eu/os_dep/usb_intf.c:158:

WARNING: Unnecessary ftrace-like logging - prefer using ftrace
177: FILE: drivers/staging/rtl8188eu/os_dep/usb_intf.c:177:
+       pr_debug("<=== %s\n", __func__);

and removes another line of unnecessary logging, which was not
identified by checkpatch.pl in an automated manner.

Signed-off-by: Jan Gruber <j4n6ru@gmail.com>
Link: https://lore.kernel.org/r/20210705172101.239899-1-j4n6ru@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>