ocs_fc(4): Fix GCC build (-Wredundant-decls)

These objects are defined earlier in the same file; an extern declaration
after definition is redundant.

Broken in r331766 (introduction of ocs_fc(4)).

Sponsored by:	Dell EMC Isilon

sys/dev/ocs_fc/sli4.c

@@ -5758,9 +5758,6 @@ int32_t sli_link_is_configurable(sli4_t *sli)
 
 /* vim: set noexpandtab textwidth=120: */
 
-extern const char *SLI_QNAME[];
-extern const sli4_reg_t regmap[SLI4_REG_MAX][SLI4_MAX_IF_TYPES];
-
 /**
  * @ingroup sli_fc
  * @brief Write an FCOE_WQ_CREATE command.