Make vold compile with -Werror -Wall.

-Wno-missing-field-initializers is used as well, but that is an
overzealous warning from initializing structs with {0} and not a
real warning.

bug 18736778 and 16868177

Change-Id: Iffde89cd7200d9a11193e1614f1819f9fcace30a
diff --git a/Devmapper.cpp b/Devmapper.cpp
index 700e538..703902f 100644
--- a/Devmapper.cpp
+++ b/Devmapper.cpp
@@ -296,7 +296,7 @@
 
 void *Devmapper::_align(void *ptr, unsigned int a)
 {
-        register unsigned long agn = --a;
+        unsigned long agn = --a;
 
         return (void *) (((unsigned long) ptr + agn) & ~agn);
 }