staging: rtl8188eu: Fix module loading from tasklet for WEP encryption

Commit 2b2ea09e ("staging:r8188eu: Use lib80211 to decrypt WEP-frames")
causes scheduling while atomic bugs followed by a hard freeze whenever
the driver tries to connect to a WEP-encrypted network. Experimentation
showed that the freezes were eliminated when module lib80211 was
preloaded, which can be forced by calling lib80211_get_crypto_ops()
directly rather than indirectly through try_then_request_module().
With this change, no BUG messages are logged.

Fixes: 2b2ea09e ("staging:r8188eu: Use lib80211 to decrypt WEP-frames")
Cc: Stable <stable@vger.kernel.org> # v4.17+
Cc: Michael Straube <straube.linux@gmail.com>
Cc: Ivan Safonov <insafonov@gmail.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/core/rtw_security.c

@@ -154,7 +154,7 @@ void rtw_wep_encrypt(struct adapter *padapter, u8 *pxmitframe)
 
 	pframe = ((struct xmit_frame *)pxmitframe)->buf_addr + hw_hdr_offset;
 
-	crypto_ops = try_then_request_module(lib80211_get_crypto_ops("WEP"), "lib80211_crypt_wep");
+	crypto_ops = lib80211_get_crypto_ops("WEP");
 
 	if (!crypto_ops)
 		return;
@@ -210,7 +210,7 @@ int rtw_wep_decrypt(struct adapter  *padapter, u8 *precvframe)
 		void *crypto_private = NULL;
 		int status = _SUCCESS;
 		const int keyindex = prxattrib->key_index;
-		struct lib80211_crypto_ops *crypto_ops = try_then_request_module(lib80211_get_crypto_ops("WEP"), "lib80211_crypt_wep");
+		struct lib80211_crypto_ops *crypto_ops = lib80211_get_crypto_ops("WEP");
 		char iv[4], icv[4];
 
 		if (!crypto_ops) {