Previously, the return value of sscanf() was treated as an indication of
the digits it would have read. Yet, sscanf() only returns the amount of
valid matches.
Therefore, introduce a function to calculate the decimal digits of the
read number and use this one to commence a colon search, as originally
intended.
Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>