Staging: hv: osd: remove physical address wrapper functions

Use the real functions the kernel provides, so that people can see what
is actually going on in the code easier.

Cc: Bill Pemberton <wfp5p@virginia.edu>
Cc: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/hv/Channel.c b/drivers/staging/hv/Channel.c
index 61fc345..5b87643 100644
--- a/drivers/staging/hv/Channel.c
+++ b/drivers/staging/hv/Channel.c
@@ -416,7 +416,7 @@
 	ASSERT( (Size & (PAGE_SIZE-1)) == 0);
 
 	pageCount = Size >> PAGE_SHIFT;
-	pfn = GetPhysicalAddress(Kbuffer) >> PAGE_SHIFT;
+	pfn = virt_to_phys(Kbuffer) >> PAGE_SHIFT;
 
 	/* do we need a gpadl body msg */
 	pfnSize = MAX_SIZE_CHANNEL_MESSAGE - sizeof(VMBUS_CHANNEL_GPADL_HEADER) - sizeof(GPA_RANGE);