[Bug ada/124192] fix documentation of Max_Tasks restriction at local level

[liam at liampwll dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124192

--- Comment #3 from Liam Powell <liam at liampwll dot com> ---
It doesn't make sense as Mas_Tasks is defined as: "Specifies the maximum number
of task creations that may be executed ..."

This does not work at compile time when tasks may be created dynamically.