vold: fix 64 bit ioctl error

Changing the num_sectors used in ioctl with BLKGETSIZE because
the kernel expects an unsigned long type and then changes 64 bits
with a 64 bits userspace. This overwrites what's located close to
the parameter location if any.

Change-Id: I78fd61a1084de2741f39b926aa436462518709a0
Signed-off-by: Mateusz Nowak <mateusz.nowak@intel.com>
Signed-off-by: Zhiquan Liu <zhiquan.liu@intel.com>
diff --git a/Devmapper.cpp b/Devmapper.cpp
index 703eade..e56a4da 100644
--- a/Devmapper.cpp
+++ b/Devmapper.cpp
@@ -164,7 +164,7 @@
 }
 
 int Devmapper::create(const char *name, const char *loopFile, const char *key,
-                      unsigned int numSectors, char *ubuffer, size_t len) {
+                      unsigned long numSectors, char *ubuffer, size_t len) {
     char *buffer = (char *) malloc(DEVMAPPER_BUFFER_SIZE);
     if (!buffer) {
         SLOGE("Error allocating memory (%s)", strerror(errno));