Strip trailing '\n' from error_report()'s first argument

error_report() prepends location, and appends a newline.  The message
constructed from the arguments should not contain a newline.  Fix the
obvious offenders.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
diff --git a/qemu-img.c b/qemu-img.c
index 4f162d1..1a37828 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -690,12 +690,12 @@
 
     if (snapshot_name != NULL) {
         if (bs_n > 1) {
-            error_report("No support for concatenating multiple snapshot\n");
+            error_report("No support for concatenating multiple snapshot");
             ret = -1;
             goto out;
         }
         if (bdrv_snapshot_load_tmp(bs[0], snapshot_name) < 0) {
-            error_report("Failed to load snapshot\n");
+            error_report("Failed to load snapshot");
             ret = -1;
             goto out;
         }