perf/x86/amd/uncore: Fix uninitialized return value in amd_uncore_init()

Some of the error paths in this function return don't initialize the
error code.  Return -ENODEV by default.

Fixes: d6389d3c ("perf/x86/amd/uncore: Refactor uncore management")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/cec62eba-c4b8-4cb7-9671-58894dd4b974@moroto.mountain

arch/x86/events/amd/uncore.c

@@ -1009,7 +1009,8 @@ static struct amd_uncore uncores[UNCORE_TYPE_MAX] = {
 static int __init amd_uncore_init(void)
 {
 	struct amd_uncore *uncore;
-	int ret, i;
+	int ret = -ENODEV;
+	int i;
 
 	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
 	    boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)