arm: cortex-m: minor doc updates in swap_helper.S

Inline some minor clarifications regarding the
Lazy Stacking feature in the cortex-m pendSV
handler, for ease of understanding. Also, fix
some minor style issues in comments.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
1 file changed