Fixes errors like this when building with CMake (which uses -Wall,
-Wextra and -Werror) on Ubuntu 21.10 with gcc 11.2.0.
../lib/sfio/sfdisc.c:114:25: error: this ‘for’ clause does not guard... [-Werror=misleading-indentation]
114 | { for(d = f->disc; d && !d->iof; d = d->disc) ; \
| ^~~
../lib/sfio/sfdisc.c:119:9: note: in expansion of macro ‘REINIT’
119 | REINIT(oreadf, readf, Sfread_f);
| ^~~~~~
../lib/sfio/sfdisc.c:115:25: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘for’
115 | if(DISCF(d,iof,type) != oiof) \
| ^~
../lib/sfio/sfdisc.c:119:9: note: in expansion of macro ‘REINIT’
119 | REINIT(oreadf, readf, Sfread_f);
| ^~~~~~
#define DISCF(dst,iof,type) (dst ? dst->iof : NULL)
#define REINIT(oiof,iof,type) \
if(!reinit) \
- { for(d = f->disc; d && !d->iof; d = d->disc) ; \
+ { for(d = f->disc; d && !d->iof; d = d->disc) \
+ ; \
if(DISCF(d,iof,type) != oiof) \
reinit = 1; \
}