[KERNEL32] Remove a pointless SEH in VirtualAllocEx (#5117)

Win2K3 just wraps in SEH only this syscall, which appears pointless
and was removed since NT6.0. We remove it too as an experiment.
Revert the change that added SEH here from commit 6d97180 (r52899).

dll/win32/kernel32/client/virtmem.c

@@ -37,22 +37,13 @@ VirtualAllocEx(IN HANDLE hProcess,
         return NULL;
     }
 
-    /* Handle any possible exceptions */
-    _SEH2_TRY
-    {
-        /* Allocate the memory */
-        Status = NtAllocateVirtualMemory(hProcess,
-                                         &lpAddress,
-                                         0,
-                                         &dwSize,
-                                         flAllocationType,
-                                         flProtect);
-    }
-    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
-    {
-        Status = _SEH2_GetExceptionCode();
-    }
-    _SEH2_END;
+    /* Allocate the memory */
+    Status = NtAllocateVirtualMemory(hProcess,
+                                     &lpAddress,
+                                     0,
+                                     &dwSize,
+                                     flAllocationType,
+                                     flProtect);
 
     /* Check for status */
     if (!NT_SUCCESS(Status))