fixed syntax error in ccall

Author: AhmedYKadah

src/erf.jl

@@ -25,8 +25,8 @@ for f in (:erf, :erfc)
     end
 end
 
-    _erfc(x::Float64) = ccall((_erfc, libopenlibm), Float64, (Float64,), x)
-    _erfc(x::Float32) = ccall((_erfcf, libopenlibm), Float32, (Float32,), x)
+    _erfc(x::Float64) = ccall((erfc, libopenlibm), Float64, (Float64,), x)
+    _erfc(x::Float32) = ccall((erfcf, libopenlibm), Float32, (Float32,), x)
     _erfc(x::Float16) = Float16(_erfc(Float32(x)))
 
 for f in (:erfcx, :erfi, :dawson, :faddeeva)