openmp is required only if we look explicitly for multithreaded mkl

modules/find/FindBLAS.cmake

@@ -537,15 +537,13 @@ if( (NOT BLAS_FOUND_WITH_PKGCONFIG) OR BLAS_GIVEN_BY_USER )
           endif()
         endif()
         set(BLAS_CFLAGS_OTHER "")
-        if (NOT BLA_VENDOR STREQUAL "Intel10_64lp_seq")
-          if(BLAS_FIND_REQUIRED)
-            find_package(OpenMP REQUIRED)
-          else()
-            find_package(OpenMP)
-          endif()
-          if(OPENMP_C_FLAGS)
-            list(APPEND BLAS_CFLAGS_OTHER "${OPENMP_C_FLAGS}")
-          endif()
+        if (BLA_VENDOR STREQUAL "Intel10_64lp" AND BLAS_FIND_REQUIRED)
+          find_package(OpenMP REQUIRED)
+        else()
+          find_package(OpenMP)
+        endif()
+        if(OPENMP_C_FLAGS)
+          list(APPEND BLAS_CFLAGS_OTHER "${OPENMP_C_FLAGS}")
         endif()
         if (CMAKE_C_COMPILER_ID STREQUAL "GNU")
           if (BLA_VENDOR STREQUAL "Intel10_32")