Fixed random segfault in test/3 drivers. (#788)

Details:
- Fixed a segfault in the non-gemm test drivers in test/3 that was the
  result of sometimes leaving either .n_str or .k_str fields of the
  params_t struct uninitialized, depending on the operation in question.
  For example, in test_hemm.c, init_def_params() would only initialize
  the .m_str and .n_str fields, but not the .k_str field. Even though
  hemm doesn't use a 'k' dimension, the proc_params() function (called
  via parse_cl_params()) universally attempts to convert all three into
  integers via sscanf(), which was understandably failing when one of
  those strings was a NULL pointer. I'm not sure how this code ever
  worked to begin with. Special thanks to Leick Robinson for finding and
  reporting this bug.

test/3/test_hemm.c

@@ -358,6 +358,7 @@ void init_def_params( params_t* params )
 	params->ps_str    = GLOB_DEF_PS_STR;
 	params->m_str     = GLOB_DEF_M_STR;
 	params->n_str     = GLOB_DEF_N_STR;
+	params->k_str     = GLOB_DEF_K_STR;
 
 	params->nr_str    = GLOB_DEF_NR_STR;
 

test/3/test_herk.c

@@ -336,6 +336,7 @@ void init_def_params( params_t* params )
 
 	params->ps_str    = GLOB_DEF_PS_STR;
 	params->m_str     = GLOB_DEF_M_STR;
+	params->n_str     = GLOB_DEF_N_STR;
 	params->k_str     = GLOB_DEF_K_STR;
 
 	params->nr_str    = GLOB_DEF_NR_STR;

test/3/test_trmm.c

@@ -340,6 +340,7 @@ void init_def_params( params_t* params )
 	params->ps_str    = GLOB_DEF_PS_STR;
 	params->m_str     = GLOB_DEF_M_STR;
 	params->n_str     = GLOB_DEF_N_STR;
+	params->k_str     = GLOB_DEF_K_STR;
 
 	params->nr_str    = GLOB_DEF_NR_STR;
 

test/3/test_trsm.c

@@ -343,6 +343,7 @@ void init_def_params( params_t* params )
 	params->ps_str    = GLOB_DEF_PS_STR;
 	params->m_str     = GLOB_DEF_M_STR;
 	params->n_str     = GLOB_DEF_N_STR;
+	params->k_str     = GLOB_DEF_K_STR;
 
 	params->nr_str    = GLOB_DEF_NR_STR;