[linalg.algs.blas3.rankk] Fix missing alpha in formula

Author: jensmaurer

source/numerics.tex

@@ -15073,7 +15073,7 @@
 \begin{itemdescr}
 \pnum
 \effects
-Computes a matrix $C'$ such that $C' = C + A A^H$,
+Computes a matrix $C'$ such that $C' = C + \alpha A A^H$,
 where the scalar $\alpha$ is \tcode{alpha},
 and assigns each element of $C'$ to the corresponding element of $C$.
 \end{itemdescr}