Fix UNIX client.mk build bustage on fresh pulls (but not on clobber or depend...

Fix UNIX client.mk build bustage on fresh pulls (but not on clobber or depend builds).  For some reason, cvs leaves CVS/TAG droppings all the way up to the top of the tree if you check out a branch using an alias modulename, but not if you specify the directories desired by hand.  So replaced "DirectorySDKSourceC" with "mozilla/directory/c-sdk".  a=leaf@mozilla.org.

client.mk

@@ -191,7 +191,7 @@ CVSCO_NSPR = cvs $(CVS_FLAGS) co $(NSPR_CO_FLAGS) $(CVS_CO_DATE_FLAGS) $(NSPR_CO
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 # CVS defines for the C LDAP SDK
 #
-LDAPCSDK_CO_MODULE = DirectorySDKSourceC
+LDAPCSDK_CO_MODULE = mozilla/directory/c-sdk
 LDAPCSDK_CO_FLAGS := -P
 ifdef LDAPCSDK_CO_TAG
   LDAPCSDK_CO_FLAGS := $(LDAPCSDK_CO_FLAGS) -r $(LDAPCSDK_CO_TAG)