Cleaned up generation of "Not a mutex" error messages.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@7483 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/exp-drd/drd_error.h b/exp-drd/drd_error.h
index 81e7932..e9a54c4 100644
--- a/exp-drd/drd_error.h
+++ b/exp-drd/drd_error.h
@@ -40,7 +40,8 @@
    DataRaceErr    = 1,
    MutexErr       = 2,
    CondRaceErr    = 3,
-   CondErr = 4,
+   CondErr        = 4,
+   GenericErr     = 5,
 } DrdErrorKind;
 
 /* The classification of a faulting address. */
@@ -94,6 +95,9 @@
    Addr cond;
 } CondErrInfo;
 
+typedef struct {
+} GenericErrInfo;
+
 void describe_addr(Addr const a, SizeT const len, AddrInfo* const ai);
 Char* describe_addr_text(Addr const a, SizeT const len, AddrInfo* const ai,
                          Char* const buf, UInt const n_buf);