Fix typo in proc_macro Span::eq documentation

[jam1garner]

No description provided.

[rustbot]

Hey! It looks like you've submitted a new PR for the library teams!

If this PR contains changes to any rust-lang/rust public library APIs then please comment with @rustbot label +T-libs-api -T-libs to tag it appropriately. If this PR contains changes to any unstable APIs please edit the PR description to add a link to the relevant API Change Proposal or create one if you haven't already. If you're unsure where your change falls no worries, just leave it as is and the reviewer will take a look and make a decision to forward on if necessary.

Examples of T-libs-api changes:

• Stabilizing library features
• Introducing insta-stable changes such as new implementations of existing stable traits on existing stable types
• Introducing new or changing existing unstable library APIs (excluding permanently unstable features / features without a tracking issue)
• Changing public documentation in ways that create new stability guarantees
• Changing observable runtime behavior of library APIs

[rust-highfive]

r? @petrochenkov

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[petrochenkov]

@bors r+ rollup

[bors]

📌 Commit 527f788 has been approved by petrochenkov

It is now in the queue for this repository.

[bors]

⌛ Testing commit 527f788 with merge 4af79cc...

[bors]

☀️ Test successful - checks-actions
Approved by: petrochenkov
Pushing 4af79cc to master...

[rust-timer]

Finished benchmarking commit (4af79cc): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

This benchmark run did not return any relevant results for this metric.

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean1	range	count2
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-4.5%	[-4.5%, -4.5%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-4.5%	[-4.5%, -4.5%]	1

Footnotes

1. the arithmetic mean of the percent change ↩

2. number of relevant changes ↩