[libc][errno] Remove previously added errno numbers (#92163)

Introduced in #91150. Not
needed anymore as #92041 fixed
the root cause. `ENAMETOOLONG` and `EOVERFLOW` are well defined in
`<linux/errno.h>`.

Post mortem: Due to the previously missing inclusion of
`<linux/errno.h>` (fixed with
#92041), I misinterpreted an
undefined macro issue during the development of
#91150 as being caused by a
missing definition rather than by the missing inclusion of the linux
header. I realized too late that `ENAMETOOLONG` and `EOVERFLOW` were
correctly defined in `<linux/errno.h>` and that it was my missing
inclusion that caused the problem.

Author: robincaloudis

libc/include/llvm-libc-macros/generic-error-number-macros.h

@@ -43,7 +43,5 @@
 #define EPIPE 32
 #define EDOM 33
 #define ERANGE 34
-#define ENAMETOOLONG 36
-#define EOVERFLOW 75
 
 #endif // LLVM_LIBC_MACROS_GENERIC_ERROR_NUMBER_MACROS_H