Fix misc-macro-parentheses warnings in simpleperf.

Bug: 28705665
Change-Id: I0521602cbca7eb3d2e242771da697dfab3fc727f
diff --git a/simpleperf/dwarf_unwind.cpp b/simpleperf/dwarf_unwind.cpp
index 10baeb6..ff3c1fe 100644
--- a/simpleperf/dwarf_unwind.cpp
+++ b/simpleperf/dwarf_unwind.cpp
@@ -27,7 +27,7 @@
   do {                                           \
     uint64_t value;                              \
     if (GetRegValue(regs, perf_regno, &value)) { \
-      dst = value;                               \
+      (dst) = value;                             \
     }                                            \
   } while (0)