getcfi_scn_eh_frame: Don't crash and burn when .eh_frame bits aren't there.

Trying to read non-existing bits sometimes works and normally a sanity
check will fail. But it could also lead to an unexpected crash much later
when trying to use the non-existing data.

Signed-off-by: Mark Wielaard <mjw@redhat.com>
diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 700c166..22f8b0c 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,7 @@
+2013-07-02  Mark Wielaard  <mjw@redhat.com>
+
+	* dwarf_getcfi_elf.c (getcfi_shdr): Check sh_type == SHT_PROGBITS.
+
 2013-06-26  Mark Wielaard  <mjw@redhat.com>
 
 	* libdw_visit_scopes.c (__libdw_visit_scopes): Don't reject root