YARN-6141. ppc64le on Linux doesn't trigger __linux get_executable codepath. Contributed by Sonia Garudi and Ayappan.

(cherry picked from commit bc28da65fb1c67904aa3cefd7273cb7423521014)
(cherry picked from commit ca1c0cbc62b577e03ed59efb3f9050cba59be8a0)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/native/container-executor/impl/get_executable.c

@@ -142,7 +142,7 @@ char* get_executable(char *argv0) {
   return __get_exec_sysctl(mib);
 }
 
-#elif defined(__linux)
+#elif defined(__linux__)
 
 
 char* get_executable(char *argv0) {