fix kldload error return when a module is rejected because it's statically

linked in the kernel.  When this condition is detected deep in the linker
internals the EEXIST error code that's returned is stomped on and instead
an ENOEXEC code is returned.  This makes apps like sysinstall bitch.

sys/kern/kern_linker.c

@@ -362,10 +362,18 @@ linker_load_file(const char *filename, linker_file_t *result)
 	 * Less than ideal, but tells the user whether it failed to load or
 	 * the module was not found.
 	 */
-	if (foundfile)
-		/* Format not recognized (or unloadable). */
-		error = ENOEXEC;
-	else
+	if (foundfile) {
+		/*
+		 * Format not recognized or otherwise unloadable.
+		 * When loading a module that is statically built into
+		 * the kernel EEXIST percolates back up as the return
+		 * value.  Preserve this so that apps like sysinstall
+		 * can recognize this special case and not post bogus
+		 * dialog boxes.
+		 */
+		if (error != EEXIST)
+			error = ENOEXEC;
+	} else
 		error = ENOENT;		/* Nothing found */
 out:
 	return (error);