rtlwifi: fix error handling in *_read_adapter_info()

There are nine copies of the _rtl88ee_read_adapter_info() function,
and most but not all of them cause a build warning in some configurations:

rtl8192de/hw.c: In function '_rtl92de_read_adapter_info':
rtl8192de/hw.c:1767:12: error: 'hwinfo' may be used uninitialized in this function [-Werror=maybe-uninitialized]
rtl8723ae/hw.c: In function '_rtl8723e_read_adapter_info.constprop':
rtlwifi/rtl8723ae/hw.c:1654:12: error: 'hwinfo' may be used uninitialized in this function [-Werror=maybe-uninitialized]

The problem is that when rtlefuse->epromtype is something other than
EEPROM_BOOT_EFUSE, the rest of the function uses undefined data, resulting
in random behavior later.

Apparently, in some drivers, the problem was already found and fixed
but the fix did not make it into the others.

This picks one approach to deal with the problem and applies identical
code to all 9 files, to simplify the later consolidation of those.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>