qapi: String visitor, use %f representation for floats
Currently string-output-visitor formats floats as %g, which is nice in
that trailing 0's are automatically truncated, but otherwise this causes
some issues:
- it uses 6 significant figures instead of 6 decimal places, which
means something like 155777.5 (which even has an exact floating point
representation) will be rounded to 155778 when converted to a string.
- output will be presented in scientific notation when the normalized
form requires a 10^x multiplier. Not a huge deal, but arguably less
readable for command-line arguments.
- due to using scientific notation for numbers requiring more than 6
significant figures, instead of hard-defined decimal places, it
fails a lot of the test-visitor-serialization unit tests for floats.
Instead, let's just use %f, which is what the QJSON and the QMP visitors
use.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>