dm: blk: Rename get_device() to blk_get_device_by_str()

The current name is too generic. The function returns a block device based
on a provided string. Rename it to aid searching and make its purpose
clearer. Also add a few comments.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
diff --git a/disk/part.c b/disk/part.c
index 2466c3e..2e7adbc 100644
--- a/disk/part.c
+++ b/disk/part.c
@@ -449,8 +449,8 @@
 	return -1;
 }
 
-int get_device(const char *ifname, const char *dev_hwpart_str,
-	       struct blk_desc **dev_desc)
+int blk_get_device_by_str(const char *ifname, const char *dev_hwpart_str,
+			  struct blk_desc **dev_desc)
 {
 	char *ep;
 	char *dup_str = NULL;
@@ -598,7 +598,7 @@
 	}
 
 	/* Look up the device */
-	dev = get_device(ifname, dev_str, dev_desc);
+	dev = blk_get_device_by_str(ifname, dev_str, dev_desc);
 	if (dev < 0)
 		goto cleanup;