kernel: wifi: brcmfmac: Check the return value of of_property_read_string_index()

In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: Check the return value of ofpropertyreadstringindex Somewhen between 6.10 and 6.11 the driver started to crash on my MacBookPro14,3. The property doesn't exist and 'tmp' remains uninitialized, so we pass a random...