Allow multithreading TRMV again

revert workaround introduced for issue #1332 as the actual cause appears to be my incorrect fix from #1262 (see #1388)

interface/trmv.c

@@ -218,11 +218,8 @@ void CNAME(enum CBLAS_ORDER order, enum CBLAS_UPLO Uplo,
   buffer = (FLOAT *)blas_memory_alloc(1);
 
 #ifdef SMP
-/*  nthreads = num_cpu_avail(2);
+  nthreads = num_cpu_avail(2);
 
-FIXME trmv_thread was found to be broken, see issue 1332 */
-  nthreads = 1;
-  
   if (nthreads == 1) {
 #endif
 

interface/ztrmv.c

@@ -239,9 +239,6 @@ void CNAME(enum CBLAS_ORDER order, enum CBLAS_UPLO Uplo,
   } else
       nthreads = 1;
 
-/* FIXME TRMV multithreading appears to be broken, see issue 1332*/
-  nthreads = 1;
-
   if(nthreads > 1) {
     buffer_size = n > 16 ? 0 : n * 4 + 40;
   }