Fix markdown link

Signed-off-by: Jens Reidel <adrian@travitia.xyz>

Author: Gelbpunkt

src/doc/rustc/src/SUMMARY.md

@@ -66,7 +66,7 @@
     - [powerpc-unknown-openbsd](platform-support/powerpc-unknown-openbsd.md)
     - [powerpc-unknown-linux-muslspe](platform-support/powerpc-unknown-linux-muslspe.md)
     - [powerpc64-ibm-aix](platform-support/aix.md)
-    - [powerpc64le-unknown-linux-musl](platform-support/powerpc64-unknown-linux-musl.md)
+    - [powerpc64le-unknown-linux-musl](platform-support/powerpc64le-unknown-linux-musl.md)
     - [riscv32e*-unknown-none-elf](platform-support/riscv32e-unknown-none-elf.md)
     - [riscv32i*-unknown-none-elf](platform-support/riscv32-unknown-none-elf.md)
     - [riscv32im-risc0-zkvm-elf](platform-support/riscv32im-risc0-zkvm-elf.md)