broadcom: Remove extern from function prototypes

There are a mix of function prototypes with and without extern
in the kernel sources.  Standardize on not using extern for
function prototypes.

Function prototypes don't need to be written with extern.
extern is assumed by the compiler.  Its use is as unnecessary as
using auto to declare automatic/local variables in a block.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/cnic_if.h

@@ -353,8 +353,8 @@ struct cnic_ulp_ops {
 	atomic_t ref_count;
 };
 
-extern int cnic_register_driver(int ulp_type, struct cnic_ulp_ops *ulp_ops);
+int cnic_register_driver(int ulp_type, struct cnic_ulp_ops *ulp_ops);
 
-extern int cnic_unregister_driver(int ulp_type);
+int cnic_unregister_driver(int ulp_type);
 
 #endif