acos.3, acosh.3, asin.3, asinh.3, atan.3, atan2.3, atanh.3, cabs.3, cacos.3, cacosh...

acos.3, acosh.3, asin.3, asinh.3, atan.3, atan2.3, atanh.3, cabs.3, cacos.3, cacosh.3, casin.3, casinh.3, catan.3, catanh.3, cbrt.3, cexp.3, cimag.3, conj.3, copysign.3, cos.3, cosh.3, cpow.3, creal.3, erf.3, erfc.3, exp.3, exp10.2, exp2.3, expm1.3, fma.3, fmod.3, frexp.3, hypot.3, ldexp.3, lgamma.3, log.3, log10.3, log1p.3, log2.3, modf.3, pow.3, pow10.3, remainder.3, significand.3, sin.3, sinh.3, sqrt.3, tan.3, tanh.3, tgamma.3: wfix: use consistent wording to describe functions

exp10.3, lgamma.3, modf.3, pow10.3, remainder.3, significand.3:dd
Where a page describes multiple math functions with float, double,
and long double variants, just describe them as "These functions"
rather than describing in terms of just the double variant.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>