armv7m: Don't enforce use of kernel for qtest

Adopt error_report().
Signed-off-by: NAndreas Färber <afaerber@suse.de>

hw/arm/armv7m.c

@@ -11,6 +11,8 @@
 #include "hw/arm/arm.h"
 #include "hw/loader.h"
 #include "elf.h"
+#include "sysemu/qtest.h"
+#include "qemu/error-report.h"
 
 /* Bitbanded IO.  Each word corresponds to a single bit.  */
 
@@ -232,21 +234,22 @@ qemu_irq *armv7m_init(MemoryRegion *address_space_mem,
     big_endian = 0;
 #endif
 
-    if (!kernel_filename) {
+    if (!kernel_filename && !qtest_enabled()) {
         fprintf(stderr, "Guest image must be specified (using -kernel)\n");
         exit(1);
     }
 
-    image_size = load_elf(kernel_filename, NULL, NULL, &entry, &lowaddr,
-                          NULL, big_endian, ELF_MACHINE, 1);
-    if (image_size < 0) {
-        image_size = load_image_targphys(kernel_filename, 0, flash_size);
-	lowaddr = 0;
-    }
-    if (image_size < 0) {
-        fprintf(stderr, "qemu: could not load kernel '%s'\n",
-                kernel_filename);
-        exit(1);
+    if (kernel_filename) {
+        image_size = load_elf(kernel_filename, NULL, NULL, &entry, &lowaddr,
+                              NULL, big_endian, ELF_MACHINE, 1);
+        if (image_size < 0) {
+            image_size = load_image_targphys(kernel_filename, 0, flash_size);
+            lowaddr = 0;
+        }
+        if (image_size < 0) {
+            error_report("Could not load kernel '%s'", kernel_filename);
+            exit(1);
+        }
     }
 
     /* Hack to map an additional page of ram at the top of the address