SUNRPC: remove duplicate include

Remove linux/sunrpc/auth_gss.h which is included more than once
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

net/sunrpc/auth_gss/trace.c

@@ -9,7 +9,6 @@
 #include <linux/sunrpc/svc_xprt.h>
 #include <linux/sunrpc/auth_gss.h>
 #include <linux/sunrpc/gss_err.h>
-#include <linux/sunrpc/auth_gss.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/rpcgss.h>