glsl/glcpp: Fix off-by-one error in column in first-line error messages

glsl/glcpp: Fix off-by-one error in column in first-line error messages

For the first line we were initializing the column to 1, but for all
subsequent lines we were initializing the column to 0. The column number is
advanced for each token read before any error message is printed. So the 0
value is the correct initialization, (so that the first column is reported as
column 1).

With this extremely minor change, many of the .expected files are updated such
that error messages for the first line now have the correct column number in
them.

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>