Fix misc-macro-parentheses warnings in lmkd.

Bug: 28705665
Change-Id: I43388c0f9fdc8c2a0c0f4495f96bbc27e3de8a1d
diff --git a/lmkd/lmkd.c b/lmkd/lmkd.c
index aa3db8a..37fbdb8 100644
--- a/lmkd/lmkd.c
+++ b/lmkd/lmkd.c
@@ -114,7 +114,7 @@
 static struct proc *pidhash[PIDHASH_SZ];
 #define pid_hashfn(x) ((((x) >> 8) ^ (x)) & (PIDHASH_SZ - 1))
 
-#define ADJTOSLOT(adj) (adj + -OOM_ADJUST_MIN)
+#define ADJTOSLOT(adj) ((adj) + -OOM_ADJUST_MIN)
 static struct adjslot_list procadjslot_list[ADJTOSLOT(OOM_ADJUST_MAX) + 1];
 
 /*