IB/hfi1: Fix sdma_event_names[] build warning

sdma_event_names[] is only used within CONFIG_SDMA_VERBOSITY ifdefs, so
when CONFIG_SDMA_VERBOSITY is disabled, it results in the following
0-day build warning:
>> drivers/infiniband/hw/hfi1/sdma.c:137:27: warning: 'sdma_event_names'
>> defined but not used [-Wunused-const-variable=]
    static const char * const sdma_event_names[] = {
                              ^~~~~~~~~~~~~~~~
This occurs on the following compiler:
compiler: gcc-6 (Debian 6.1.1-1) 6.1.1 20160430

For more information check:
https://lists.01.org/pipermail/kbuild-all/2016-May/020060.html

Fix this warning by defining sdma_event_name[] only within the
CONFIG_SDMA_VERBOSITY ifdefs.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Reviewed-by: NMike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: NDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: NJubin John <jubin.john@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

drivers/staging/rdma/hfi1/sdma.c

@@ -134,6 +134,7 @@ static const char * const sdma_state_names[] = {
 	[sdma_state_s99_running]                = "s99_Running",
 };
 
+#ifdef CONFIG_SDMA_VERBOSITY
 static const char * const sdma_event_names[] = {
 	[sdma_event_e00_go_hw_down]   = "e00_GoHwDown",
 	[sdma_event_e10_go_hw_start]  = "e10_GoHwStart",
@@ -150,6 +151,7 @@ static const char * const sdma_event_names[] = {
 	[sdma_event_e85_link_down]    = "e85_LinkDown",
 	[sdma_event_e90_sw_halted]    = "e90_SwHalted",
 };
+#endif
 
 static const struct sdma_set_state_action sdma_action_table[] = {
 	[sdma_state_s00_hw_down] = {