[fix #118] protect macro definitions

Author: dgraziotin

src/mbpfan.c

@@ -41,8 +41,8 @@
 #include "settings.h"
 
 /* lazy min/max... */
-#define min(a,b) a < b ? a : b
-#define max(a,b) a > b ? a : b
+#define min(a,b) ((a) < (b) ? (a) : (b))
+#define max(a,b) ((a) > (b) ? (a) : (b))
 
 int min_fan_speed = 2000;
 int max_fan_speed = 6200;