Declare the p_mt_info param as a pointer to const

Declare the p_mt_info parameter of av1_get_num_mod_workers_for_alloc()
as a pointer to const. This helps code analysis.

Change-Id: I28ee5e389cd252fdc25889739639038dec484ff7

av1/encoder/ethread.c

diff --git a/av1/encoder/ethread.c b/av1/encoder/ethread.c
index c494da4..fb9b85a 100644
--- a/av1/encoder/ethread.c
+++ b/av1/encoder/ethread.c
@@ -916,7 +916,7 @@
 
 // Computes the number of workers to be considered while allocating memory for a
 // multi-threaded module under FPMT.
-int av1_get_num_mod_workers_for_alloc(PrimaryMultiThreadInfo *const p_mt_info,
+int av1_get_num_mod_workers_for_alloc(const PrimaryMultiThreadInfo *p_mt_info,
                                       MULTI_THREADED_MODULES mod_name) {
   int num_mod_workers = p_mt_info->num_mod_workers[mod_name];
   if (p_mt_info->num_mod_workers[MOD_FRAME_ENC] > 1) {

av1/encoder/ethread.h

diff --git a/av1/encoder/ethread.h b/av1/encoder/ethread.h
index f93e843..97edb64 100644
--- a/av1/encoder/ethread.h
+++ b/av1/encoder/ethread.h
@@ -98,7 +98,7 @@
 void av1_init_mt_sync(AV1_COMP *cpi, int is_first_pass);
 #endif  // CONFIG_MULTITHREAD
 
-int av1_get_num_mod_workers_for_alloc(PrimaryMultiThreadInfo *const p_mt_info,
+int av1_get_num_mod_workers_for_alloc(const PrimaryMultiThreadInfo *p_mt_info,
                                       MULTI_THREADED_MODULES mod_name);
 
 void av1_init_tile_thread_data(AV1_PRIMARY *ppi, int is_first_pass);