Minor typo correction in finite-mixtures.qmd

`lpps` changed to `lps` to match the example code.

Author: psyguy

src/stan-users-guide/finite-mixtures.qmd

@@ -245,7 +245,7 @@ The model declares a local array variable `lps` to be size
 mixture components.  The main action is in the loop over data points
 `n`.  For each such point, the log of $\theta_k \times
 \textsf{normal}\left(y_n \mid \mu_k,\sigma_k\right)$ is calculated and added to the
-array `lpps`.  Then the log probability is incremented with the log
+array `lps`.  Then the log probability is incremented with the log
 sum of exponentials of those values.
 
 ## Vectorizing mixtures