[OpenMP] Disable load balance on Haiku (#136082)

Haiku does not have a means of retrieving the desired information
and the -1 setting causes the code to fallback anyway.

openmp/runtime/src/kmp_config.h.cmake

@@ -120,7 +120,7 @@
 #define KMP_ASM_INTRINS 1
 #define USE_ITT_BUILD LIBOMP_USE_ITT_NOTIFY
 #define INTEL_ITTNOTIFY_PREFIX __kmp_itt_
-#if ! KMP_MIC
+#if ! (KMP_MIC || KMP_OS_HAIKU)
 # define USE_LOAD_BALANCE 1
 #endif
 #if ! (KMP_OS_WINDOWS || KMP_OS_DARWIN)

openmp/runtime/src/z_Linux_util.cpp

@@ -2522,10 +2522,6 @@ int __kmp_get_load_balance(int max) {
   return running_threads;
 }
 
-#elif KMP_OS_HAIKU
-
-int __kmp_get_load_balance(int max) { return -1; }
-
 #else // Linux* OS
 
 // The function returns number of running (not sleeping) threads, or -1 in case