Macintosh HD partition size wrong

Hi!

Yesterday I figured to remove Windows from my MacBook Air.

Opened the Boot Camp Assistant and pressed remove on the Windows partition.

Something went wrong and I got an error from what I understood that the Windows partition was not removed.

However after booting the laptop "About This Mac - Storage" shows now Macintosh HD maximum size as 186GB (what it was with Windows partition) as the full storage is 251 GB.

Please help me, does this affect my Mac's maximum storage negatively (if so, how to fix this) or does this have any more than visual effect at all.