[flang][mlir] Cleaning up the atomic-control testcase (#162149)

The testcase tests atomicupdate header which is not required for testing
atomic control attributes. This induces failures due to unrelated
changes (like changes in atomic update clauses). This PR removes the
unrelated test to keep it minimal.

Author: anchuraj

flang/test/Lower/OpenMP/atomic-control-options.f90

@@ -8,25 +8,17 @@ program test
     threads = 128
     A = 0
     B = 0
-    !UNSAFE-FP-ATOMICS: omp.atomic.update %{{.*}} : !fir.ref<i32> {
     !UNSAFE-FP-ATOMICS: } {atomic_control = #omp.atomic_control<ignore_denormal_mode = true>}
-    !IGNORE-DENORMAL: omp.atomic.update %{{.*}} : !fir.ref<i32> {
     !IGNORE-DENORMAL: } {atomic_control = #omp.atomic_control<ignore_denormal_mode = true>}
-    !FINE-GRAINED-MEMORY: omp.atomic.update %{{.*}} : !fir.ref<i32> {
     !FINE-GRAINED-MEMORY: } {atomic_control = #omp.atomic_control<fine_grained_memory = true>}
-    !REMOTE-MEMORY: omp.atomic.update %{{.*}} : !fir.ref<i32> {
     !REMOTE-MEMORY: } {atomic_control = #omp.atomic_control<remote_memory = true>}
     !$omp target parallel num_threads(threads)
     !$omp atomic
     A =  A + 1
     !$omp end target parallel
-    !UNSAFE-FP-ATOMICS: omp.atomic.update %{{.*}} : !fir.ref<i32> {
     !UNSAFE-FP-ATOMICS: } {atomic_control = #omp.atomic_control<ignore_denormal_mode = true>}
-    !IGNORE-DENORMAL: omp.atomic.update %{{.*}} : !fir.ref<i32> {
     !IGNORE-DENORMAL: } {atomic_control = #omp.atomic_control<ignore_denormal_mode = true>}
-    !FINE-GRAINED-MEMORY: omp.atomic.update %{{.*}} : !fir.ref<i32> {
     !FINE-GRAINED-MEMORY: } {atomic_control = #omp.atomic_control<fine_grained_memory = true>}
-    !REMOTE-MEMORY: omp.atomic.update %{{.*}} : !fir.ref<i32> {
     !REMOTE-MEMORY: } {atomic_control = #omp.atomic_control<remote_memory = true>}
     !$omp target parallel num_threads(threads)
     !$omp atomic capture