Handle the result of posix_fallocate system call

src/util/system.cpp

@@ -1089,11 +1089,12 @@ void AllocateFileRange(FILE *file, unsigned int offset, unsigned int length) {
         fcntl(fileno(file), F_PREALLOCATE, &fst);
     }
     ftruncate(fileno(file), fst.fst_length);
-#elif defined(__linux__)
+#else
+    #if defined(__linux__)
     // Version using posix_fallocate
     off_t nEndPos = (off_t)offset + length;
-    posix_fallocate(fileno(file), 0, nEndPos);
+    if (0 == posix_fallocate(fileno(file), 0, nEndPos)) return;
-#else
+    #endif
     // Fallback version
     // TODO: just write one byte per block
     static const char buf[65536] = {};