Fix for the invalid linux_banner pointer issue

Currently, crash may fail with the following error:

  # ./crash -s vmlinux vmcore
  WARNING: invalid linux_banner pointer: 65762078756e694c
  crash: vmlinux and vmcore do not match!

The reason is that the type of the symbol in the data segment may be
defined as 'D' or 'd'. The crash only handled the type 'D', but it
didn't deal with the type 'd'. For example:

  # nm vmlinux | grep linux_banner
  ffffffff827cfa80 d linux_banner

It has been observed that a vmlinux compiled by clang has this type.
Let's add the type 'd' recognition to solve such issue.

Signed-off-by: Lianbo Jiang <lijiang@redhat.com>

kernel.c

@@ -1060,7 +1060,7 @@ verify_version(void)
 	if (!(sp = symbol_search("linux_banner")))
 		error(FATAL, "linux_banner symbol does not exist?\n");
 	else if ((sp->type == 'R') || (sp->type == 'r') ||
-		(THIS_KERNEL_VERSION >= LINUX(2,6,11) && sp->type == 'D') ||
+		(THIS_KERNEL_VERSION >= LINUX(2,6,11) && (sp->type == 'D' || sp->type == 'd')) ||
 		 (machine_type("ARM") && sp->type == 'T') ||
 		 (machine_type("ARM64")))
 		linux_banner = symbol_value("linux_banner");