regulator: core: Remove redundant assignment to variable possible_uV

regulator: core: Remove redundant assignment to variable possible_uV

The variable possible_uV being assigned a value that is never read, the
control flow via the following goto statement takes a path where the
variable is not accessed. The assignment is redundant and can be removed.

Cleans up clang scan build warning:
drivers/regulator/core.c:3935:3: warning: Value stored to 'possible_uV'
is never read [deadcode.DeadStores]

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://msgid.link/r/20240216134918.2108262-1-colin.i.king@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>